In the early 1980s Tom Williams, while a member of the GRIP project, built the GRINCH system for the ab-initio interpretation of electron density maps. Williams' system was based on work by Drs. Jonathan Greer, Carroll Johnson, and Stanley Swanson for representing electron density by marking the ridges of high local density. At least 50 copies of this system were disseminated to the crystallographic community. Juraj Horacek of the current GRIP project team is re-examining this ridge line approach to ab-initio electron density interpretation using new, more powerful ridge line finding mathematics developed in our department by David Eberly for the analysis of medical images. Our new approach is distinguished from prior work in that we do not simply connect critical points but actually trace the ridges of high density through an interpolated function. This should help us avoid some kinds of common errors in map interpretation. We expect this work to lead to both new representations for electron density and to new methodologies for its interpretation as a molecular structure. We have been consulting with Dr. Gitay Kryger to identify what facilities might be useful in this system.